Ohioceras is an extinct suborthochonic nautiloid from the Silurian of Ohio

Ohio

Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

 belonging to the orthoceroid

Orthoceratoidea

The Orthoceratoidea is a superorder , sometimes considered an infraclass or even a subclass, that comprizes nautiloid orders that have orthoconic to slightly cyrtoconic shells and central to subcentral siphuncles in which there may be internal deposits...

 family Kionoceratidae

Kionoceratidae

Kionoceratidae is a family in the Orthocerida, proposed by Hyatt in 1900 for genera characterized by prominent ornamentation in the form of longitudinal ribs, ridges, or lirae, or combinations thereof, sometimes with similar transverse ornament or faint transverse annulations.When Kionoceratidae...

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Ohioceras is characterized by a slightly curved longiconic shell with a circular to slightly depressed cross section. The surface is lined with broad, low, longitudinal ribs separated by distinct shallow grooves. The siphuncle is subcentral, apparently orthochoanitic.

References

• Sweet, Walter C. 1964. Nautiloidea-Orthocerida. Treatise on Invertebrate Paleontology, Part K. Geological Soc of America, and Univ Kansas Press.
• Ohioceras -Paleobio db.